Transition metal complexes of platinum(II), palladium(II), platinum(IV), gold(I), gold(III), rhodium(III), iridium(III), and lower oxidation states of rhodium and iridium will be prepared and evaluated for anti-tumor activity. A wide variety of ligands will be used, including ligands which also exhibit anti-tumor activity without complexation to the metal. X-ray structural studies will be carried out. The properties of the complexes in solution and their interactions with nucleobases and other biologically important molecules will be studied. Products of these interactions which can be crystallized will be subjected to X-ray structural analysis.